Since the beginning of the economic recession, fewer consumers are purchasing new cars than in years previous. In fact, in 2008, new car sales in the U.S. dropped by more than 18 percent compared to 2007.

Fewer new car sales means that more people are now buying used cars and are taking greater care of their purchase. If you plan on buying a used car in New Jersey, there are several key methods of protecting your investment.

Almost every expert will tell you that the best way to insure the health of your vehicle is to change the oil on a regular basis.

“Changing your vehicle’s oil is one of the most important things you can do to avoid bringing large bags of money to your mechanic later on,” says Cars.com.

Owner’s manual recommendations for oil changes will vary anywhere from 3,000 to 10,000 miles. However, you may want to consider changing your oil more frequently if you drive aggressively, live in extremely hot or cold climates or commonly carry heavy loads, according to the news source.

Another great way to increase the life expectancy of a used car is to change the air filter on a regular basis.

An air filter, which costs roughly $15 at any auto parts store, should be changed every 15,000 miles, says AOL Autos.

“What people don’t realize is that [driving with an old filter is] like choking your engine,” says Lori Johnson, owner of Ladies Start Your Engines, an automotive repair class for women.

“If air can’t get into the engine because it’s blocked by this dirty air filter, then you’re not going to get as good of performance, and you might even feel hesitation when you’re driving, or it will just feel like the car is dragging,” she added.

Moreover, keeping a careful eye on your transmission is one of the best ways to save costly trips to the mechanic. An automatic transmission is one of the most complicated and least reliable parts of a car.

To save wear and tear on your transmission, you should never change gears until the car comes to a complete stop, always hold the brake down when shifting from park and regularly check your parking spot for leaks. Also, an automatic transmission can be damaged if your vehicle is improperly towed. Be certain to take your car out of four-wheel drive before it is taken away.